Figure 2-7.

Finding the vanishing points for incline lines

b. To locate the inclined vanishing points, extend if necessary the

vertical lines A-B, C-D as shown in Figure 2-7 through the horizontal right

and left vanishing points.

Along these vertical lines will fall all the

vanishing points for the inclined lines and planes. Our problem now is to

find where the VPs fall on the vertical lines. As we view the object all of

the planes are inclined to the right; thus their vanishing points will fall

on the right vertical line C-D. From line SP-Y, construct angle "a" equal

to the inclined plane 1-2-3-4 in the elevation view.

Extend the line

defining this angle beyond line C-D. Construct a perpendicular to this line

intersection C-D at Y. Using a compass, lay off this perpendicular distance

on C-D from the VPR. This now is the VPR 1 for the inclined plane 1-2-3-4.

Proceed with this method on the remaining inclined planes.

Finish the

perspective projection as shown in Figure 2-7.